John Chrysostom

"Choosing rather" (he says) "to suffer affliction with the people of God." For ye indeed suffer on your own account, but he "chose" to suffer for others; and voluntarily threw himself into so many dangers, when it was in his power both to live religiously, and to enjoy good things. …

Homily on Hebrews 26 ↗

Theophylact of Ohrid

He arrived at the example most dear to them — that of Moses, which is why he dwells on it at greater length. The structure of his thought is as follows: "By faith Moses refused to be called the son of Pharaoh's daughter." When? "When he was come to years," that is, having already reached manhood. Evidently because he hoped to receive something greater in return. The word "refused" shows a strong hatred and inner aversion to the decrees of the king. See how he calls it sin — not to suffer together with one's brethren. …

Commentary on Hebrews ↗

Oecumenius

"to enjoy the momentary pleasures of sin," He called it a sin, not to collaborate or to suffer together with the people of God: not to enjoy the benefits of this sin. Whose? So that he would not be afflicted with the sufferings of the people of God.

The Pseudo-Oecumenian Catena on Hebrews ↗