The first occurrence.
And YHVH said: My Spirit shall not always strive with man, for that he also is flesh: yet his days shall be a hundred and twenty years. Gen 6:3
The primitive root.
Strong’s H1777 דין diyn, a primitive root meaning, “to judge, to plead the cause.” The 3-letter root is dalet + yud + nun.
dalet ד = door, thus enter, move, hang
yud י = closed hand, thus work, throw, worship
nun נ ן = seed, thus continue, heir, son
In the days of Patriarchs, the father or eldest son of the tribe, the one who received the birthright and blessing of the father, would sit in the door of his tent, and the sons of the tribe would come to him with their disputes, and he would render judgment between them, which was binding. Even in later days you read of the elders sitting in the gate, that is, the door of the city, where the same function of dispensing wisdom, and of rendering decisions, was carried out (see Est 2:21, 3:3). The parable is of the door (dalet) where the hand was closed (yud) to the son (nun); i.e. rendering judgment.