Before his demise Avraham divides up his possessions among his children. To Yitzchak, who was going to carry on his traditions and his teachings of Hashem: VAYITEN AVRAHAM ET KOL ASHER LO LEYITZCHAK, “ Avraham gave all that he had to Yitzchak. (Gen. 25,5) To his other children, whom he had from all the other wives, he gave: MATANOT, “…gifts…”. (Gen. 25,6) Since this was an inheritance why use the terminology “gifts”? To Yitzchak he gave “all he had” and to the others he gave “gifts”.
Avraham was a wealthy man. The Torah testifies this. He made his wealth from two different sources. His major wealth cme from his own work, his own labor, what we would call his regular income. He also got great gifts and wealth from Pharaoh when he sent him away after the incident with Sarah.
The Kli Yaker explains that to Yitzchak he gave what he earned on his own initiative, from his own toil. To the others he gave the “gifts” he had received. The gifts he gave to those who would not carry on his traditions. The gifts he got he gave back to the source from which it came, the non-Jewish source.