How was Hashem's hand heavy on him?
Rashi: Fear of Your hand and decrees was heavy on me.
Radak: I fear lest You punish me greatly, for my sin was great. Even though David received a great punishment in this world, he worried lest the sin was not finished, and he will be punished for it in the world to come.
What is the meaning of "Nehpach l'Shadi"?
Rashi citing Dunash: My moisture dried up. Also "Leshad ha'Shamen" (Bamidbar 11:8) is the moisture of oil.
Rashi citing Menachem: It is an expression of Shedidah (plundering), like "mi'Shod Aniyim" (12:6).
Radak: My flesh and liver weakened. The fat dried. Shadi is the good fat and moisture.
Malbim: Via the lack of rain, all moisture of the ground and Peros dried - because I did not confess my sin.
What are "Charbonei Kayitz"?
Rashi: Until it dries in the heat of summer, due to worry about the heaviness of Your hand; I was worried about my sin.
Why does it say "Selah"?
Malbim: This completes the matter.
