If I have lifted up my hand against the fatherless, even when I saw myself superior in the gate:

If I have lifted up my hand against an orphan, because I saw my help in the gate:

If I have waved at the fatherless my hand, When I see in him the gate of my court,

If my hand had been lifted up against him who had done no wrong, when I saw that I was supported by the judges;

if I have lifted up my hand over an orphan, even when it might seem to me that I have the advantage over him at the gate;

If I have lifted up my hand against the fatherless - That is, if I have taken advantage of my rank, influence, and power, to oppress and injure him.
When I saw my help in the gate - The gate of a city was a place of concourse; a place where debates were held, and where justice was administered. Job speaks here of that part of his life when he was clothed with authority as a magistrate, or when he had power and influence as a public man. He says that he had never abused this power to oppress the fatherless. He had never taken advantage of his influence to injure them, because he saw he had a strong party under his control, or because he had power enough to carry his point, or because he had those under him who would sustain him in an oppressive measure. This is spoken with reference to the usually feeble and defenseless condition of the orphan, as one who is deprived of his natural protector and who is, therefore, liable to be wronged by those in power.

If I have lifted up my hand against the fatherless - I have at no time opposed the orphan, nor given, in behalf of the rich and powerful, a decision against the poor, when I saw my help in the gate - when I was sitting chief on the throne of judgment, and could have done it without being called to account. There are sentiments very like these in the poem of Lebeid, one of the authors of the Moallakhat. I shall quote several verses from the elegant translation of Sir William Jones, in which the character of a charitable and bountiful chief is well described: -
"Oft have I invited a numerous company to the death of a camel bought for slaughter, to be divided with arrows of equal dimensions."
"I invite them to draw lots for a camel without a foal, and for a camel with her young one, whose flesh I distribute to all the neighbors."
"The guest and the stranger admitted to my board seem to have alighted in the sweet vale of Tebaala, luxuriant with vernal blossoms."
"The cords of my tent approaches every needy matron, worn with fatigue, like a camel doomed to die at her master's tomb, whose venture is both scanty and ragged."
"There they crown with meat (while the wintry winds contend with fierce blasts) a dish flowing like a rivulet, into which the famished orphans eagerly plunge."
"He distributes equal shares, he dispenses justice to the tribes, he is indignant when their right is diminished; and, to establish their right, often relinquishes his own."
"He acts with greatness of mind, and nobleness of heart: he sheds the dew of his liberality on those who need his assistance; he scatters around his own gains and precious spoils, the prizes of his valor." - Ver. 73-80.

If I have lifted (o) up my hand against the fatherless, when I saw my help in the gate:
(o) To oppress him and to do him harm.

If I have lifted up my hand against the fatherless,.... Either in a menacing way, threatening what he would do to them; which, from a man of wealth and authority, a civil magistrate, a judge, is very terrible to the poor and fatherless; or in order to strike him, which would be to smite with the fist of wickedness; or give a signal to others, by lifting up the hand to smite, as Ananias gave orders to smite the Apostle Paul; or thereby to give his vote against the fatherless wrongly, suffrages being sometimes made by lifting up the hands; or hereby Job signifies, that he was so far from doing the fatherless any real injury, that he had not so much as lifted up his hand, and even a finger against him:
when I saw my help in the gate; in the court of judicature held in the gate of the city, as was usual; though he knew he had the bench of judges for him, or they would give sentence in his behalf, and against the fatherless, if he did but hold up his hand, or lift up a finger to them, so ready would they be take his part and be on his side; yet he never made use of his power and interest to their detriment, or took such an advantage against them.

when--that is, "because."
I saw--that I might calculate on the "help" of a powerful party in the court of justice--("gate"), if I should be summoned by the injured fatherless.

When - When I saw I could influence the judges to do what I pleased.