Perhaps he recalled the words of Exodus 23: 19, which instructed God’s people to be willing to give their best to Jehovah.
وَقَدْ نَالَ رِضَى يَهْوَهَ وَبَرَكَتَهُ لِأَنَّهُ أَعْرَبَ عَنِ ٱلْإِيمَانِ مَهْمَا كَلَّفَ ٱلْأَمْرُ .‏