This verse from Job 31:20 is part of Job's defense, where he is listing all the ways he hasn't wronged people. He is trying to prove his innocence and righteousness. In this specific verse, he's talking about his generosity and compassion toward the poor and needy, particularly those who needed clothing. Let's break it down:

"If his heart hasn’t blessed me...": This is a hypothetical statement. Job is saying, "If the poor person's heart hasn't blessed me." The blessing would come in the form of heartfelt gratitude and prayer for Job's well-being, thanking him for his kindness.

"if he hasn’t been warmed with my sheep’s fleece...": This refers to providing clothing made from wool (sheep's fleece) to someone who was cold and in need. In the ancient world, especially in the harsh climate of the Middle East, clothing was essential for survival and comfort.

Therefore, the combined meaning is:

Job is asserting that he did provide clothing (sheep's fleece) to the poor and needy, and in return, their hearts were filled with gratitude and they blessed him. He is claiming that he was generous and kind, and the recipients of his generosity were thankful and prayed for him. If they hadn't blessed him, it would indicate that his generosity was lacking or perhaps offered with a bad attitude, rendering it meaningless.

In the context of Job's overall defense:

Job is using this example to demonstrate that he lived a righteous life, caring for the vulnerable and deserving of God's blessings, not the suffering he is currently experiencing. He is arguing that his actions prove his character is not deserving of the punishment he has received. He provided tangible aid and received heartfelt gratitude, showing a proper relationship between himself and the less fortunate.

In essence, this verse is a testament to Job's charitable nature and the positive impact he had on the lives of those less fortunate.