Rav Sadya Gaon: It is obligatory to improve [one's ways], hope and be silent.

Rashi: The prefix Vov in v'Yachil is extra, like in "v'Ayah v'Anah" (Bereishis 36:24). It is good to hope, Yidom ¹ and look forward to Hashem's salvation.

Ibn Ezra: It is good for one who seeks Hashem to bear [suffering] and fear [Him]. This is like "Dom la'Shem v'Hischolel Lo" (Tehilim 37:7). ["V'Dumam" is to wait,] like "Domu Ad Hagi'unu" (Shmuel I, 14:9).

Ri Kara: Because "Tov Hashem l'Kovav" (25) to Him, it is good to hope to Him and wait for His salvation. "V'Dumam" is like "Domu Ad Hagi'unu Aleichem."

Rid: What is good for a man is to be Yachil v'Dumam. Both of these refer to hope, like "Dom la'Shem v'Hischolel Lo."

Palgei Mayim: Hashem's good (mentioned in verse 25) comes if one hopes for His salvation. The prefix Vov in v'Yachil means 'if', like "v'Tzamis v'Halacht" (Rus 2:9).