Rashi: When Yaakov saw how the Pelishtim would poke out Shimshon's eyes and how he would pray for Heaven's help to avenge what they had done, ¹ he prayed that Hashem should answer his prayers.

Ramban: Shimshon, the last Shofet, was also the only one to fall into the hands of the enemy. When Yaakov saw that the salvation of Shimshon came to an abrupt end, he prayed for the salvation of Hashem, which lasts forever, as opposed to that of the viper and the Shefifon (which are only temporary).

Targum Yonasan: When Yaakov saw how Gid'on bar Yo'ash and Shimshon bar Mano'ach arose to save Yisrael from their enemies, he declared that it was not the salvation of these two men (whose salvation was only temporary) that he longed for, but for the salvation of Hashem (whose salvation is permanent). ²

Rashbam: He prayed for Dan's salvation when he fought against the enemy.

Hadar Zekenim: When Yaakov saw the might of Shimshon, he said that it is not proper to aggrandize oneself about his might. Shimshon did so, and immediately he became thirsty and needed to beseech Hashem (Shoftim 15:16-18). Power and victory are in Hashem's hands.

Malbim: He saw that the enemy will attack them from the back, because Yisrael are weaker than the enemy. Therefore, he prayed for Hashem's salvation.

Ha'amek Davar: Yaakov saw that this salvation [of Shimshon] is light and temporary, therefore he said that he waits for Hashem's salvation. You will be our salvation!