Genesis 31:19

And Laban had gone to shear his flock; and Rahel stole the images. For they had slain a man, a firstborn, and had cut off his head; they salted it with salt and balsams, and wrote incantations on a plate of gold, and put it under his tongue, and set it up in the wall, and it spake with them; and unto such their father bowed himself.

AND RACHEL STOLE THE TERAPHIM. Her intention was to wean her father from idol-worship. This is the language of Rashi.
Now it is possible that Laban used the teraphim for idol worship, as he himself said, Why hast thou stolen my gods? But not all teraphim were for the purpose of worship, for how could one find idolatry in the house of our lord David. That which the commentators say seems reasonable, namely, that these are vessels to receive a knowledge of the hours, and they divine with them in order to gain knowledge of future events. The word teraphim is derived from the expressions: ‘rephai’ (weak) handed; ‘nirpim’ (idle) ye are, idle. They are called “teraphim” in order to hint by their name that their words are like a weak prophecy, usually occurring as a prophecy for many days hence and turning out to be false, just as the prophets have said, For the teraphim have spoken vanity. People of little faith set them up for themselves as gods. They do not seek to know by the glorious name of the Eternal, nor do they offer their prayers to Him. Rather, their deeds are guided by divination revealed to them by the teraphim. Thus it is written, And the man Micah had a house of G-d, and he made an ephod, and teraphim, and it is further written there, Ask counsel, we pray thee, of G-d that we may know whether our way which we are going shall be prosperous,, 18:5. for they used to ask of the teraphim. Such also was the case in Israel with the ephod, for, having been accustomed to the sacred ephod they made something similar in form, and they would seek guidance of it, believe in its words, and blunder after it. Even in sickness they sought not G-d but only them. This is the meaning of the verse, And Gideon made an ephod thereof, and put it in his city, even in Ophrah; and all Israel went astray after it there; and it became a snare unto Gideon, and to his house, for they turned aside from following the Eternal. Now Laban was a diviner and an enchanter, just as he said, I have divined. His country, too, was ever a land of diviners, as it is written, For they are replenished from the east, and with soothsayers like the Philistines, and Balaam the son of Beor the diviner was from his city. And this is the meaning of, Why hast thou stolen my gods?

ותגנוב רחל את התרפים, in order that Lavan should not be able to locate the whereabouts of Yaakov and his family. We know from Hoseah 3,4 that Teraphim were credited with supplying such information to people believing in their power. Zecharyah 10,2 also refers to them as speaking, though deceptively. At any rate, they were widely consulted to provide information about the future, information of a supernatural dimension.

ולבן, the place where Lavan sheared his flocks was a distance of three days from where Yaakov tended his flocks as we know from 30,36. This is why Lavan did not hear about Yaakov’s having left until this third day after he had gone. Neither Lavan nor his sons had been home at the at time when Yaakov departed The sons of Lavan had been busy tending their father’s flocks. This is why Rachel took the Teraphim. There was no one at home to stop her from doing this.

והתרפים, they are instruments made of copper used to tell time. It was also to consult them to divine future events, although the information forthcoming often proved false. Zecharyah 10,2 already remarks on the unreliability of Teraphim in this regard. The reason the word is in the plural mode, seeing that we speak about a single object, is because it consisted of multiple layers of tablets. According to Ibn Ezra each tablet had the face of a human being and was presumed to get inspiration from celestial regions. Rachel’s objective in stealing the Teraphim was to deny Lavan knowledge about the route Yaakov had taken when he left. Yaakov had no idea that Rachel had stolen the Teraphim as we have been told explicitly in verse 32. Had he known about it he would have prevented Rachel from carrying out such a theft. He would not even have allowed her to remove anything from her father’s house unless he had given his approval, much less the Teraphim.

ותגנוב רחל את התרפים, “Rachel stole the teraphim; what precisely are “teraphim”? According to Pirke de rabbi Eliezer chapter 36, they were deities that people like Lavan worshipped. How did they originate? A firstborn male human being was slaughtered; they cut off his head, salted it (to preserve it from decomposing) using both salt and oil. They inscribed on the forehead of that slain person the name of a deity such as a demon, hung it up under the tongue of the slain person on the wall, lit candles in its honour, prostrated themselves before it, and it would start speaking to the worshipper. (presumably answering questions addressed to it, like to an oracle.) These teraphim are referred to as doing this in the Book of Zecharyah 10,2: כי התרפים דברו און, “for the teraphim spoke delusions.” Rachel stole them so that they could not speak to their father and tell him that Yaakov had fled and where he was going. Not only this; she may have used the opportunity to destroy all idols in her father’s home.