Genesis 10:9

He was a mighty rebel before the Lord; therefore it is said, From the day that the world was created there hath not been as Nimrod, mighty in hunting, and a rebel before the Lord.

HE WAS A MIGHTY HUNTER BEFORE THE ETERNAL. He ensnared the minds of people by his words, misleading them to rebel against the Omnipresent. Therefore it is said regarding any man who brazenly acts wickedly, knowing his Master and yet intentionally rebelling against Him — it is said, “This man is like Nimrod.” Thus the language of Rashi, and so is the opinion of our Rabbis.
But Rabbi Abraham ibn Ezra explained the matter in the opposite way, by way of the plain meaning of Scripture, for he interpreted the verses thus: He began to be a mighty one over the animals in hunting them. Before the Eternal, Ibn Ezra explained, means that he would build altars and offer the animals as whole-offerings before G-d. But Ibn Ezra’s words do not appear to be correct, and lo he justifieth the wicked, for our Rabbis knew by tradition of Nimrod’s wickedness.
The correct interpretation appears to me to be that Nimrod began to be a ruler by force over people, and he was the first monarch. Until his era there were no wars and no reigning monarchs; it was he who first prevailed over the people of Babylon until they crowned him. After that he went to Assyria, and he did according to his will, and magnified himself, and there he built fortified cities with his power and with his might. This is what Scripture intended when it said, And the beginning of his kingdom was Babel…and Accad…and Shinar.

'לפני ה, on the whole globe, (seeing that G’d is omnipresent) Jonah 3,3 also means that there was no other city as populous as Nineveh on earth.

לפני ה, this does not mean that he was on the same wavelength as G’d; on the contrary, such expressions are used when someone equates himself and his illusion of power with that of G’d. Compare Jonah 3,3 עיר גדולה לאלוהים, “a great city, G’d-like.” [they were G’d-like in their arrogance. Ed.]

'הוא היה גבור ציד לפני ה, the word ציד tells us that Nimrod was also a mighty hunter, i.e. that the beasts were in awe of him, too. He both shot and trapped them. People wondered how he managed this. His fame became proverbial. When one encountered an exceptionally powerful individual either then or in the future, one would compare him to Nimrod, saying that he was as great a hero as Nimrod. The meaning of the words לפני ה', is a figure of speech, i.e. if one uses this simile one pays the subject described as such a supreme compliment. Expressions such as עיר גדולה לאלוקים, (Jonah 3,3) or הררי א-ל (Psalms 36,7) and numerous other examples, all use the name of G’d to describe something as outstanding in its category, i.e. as almost divine in nature. Some scholars understand the words לפני ה'' as meaning that Nimrod offered some of the animals he had hunted to G’d as a sacrifice, acknowledging His help. Onkelos is closer to our interpretation when he writes גבר תקיף, an aggressive and powerful man.