What is the meaning of "v'Amarti Lo Ezkerenu"?
Rashi: If my heart told me not to continue my Shelichus
What is the meaning of "v'Hayah Libi k'Esh"?
Rashi: My heart was like a fire, and I needed to do my Shelichus.
Radak: Hashem's word was like fire in my heart; I would make all efforts to take it out.
Malbim: I could not forget what He told me.
What is "Atzur b'Atzmosai"?
Rashi: The fire was entered in my bones.
Why does it say "Bo'eres" (feminine) and "Atzur" (masculine)?
Radak: "Esh" can be masculine or feminine - "Ki Esh Yatz'ah me'Cheshbon" (Bamidbar 21:28), "Te'achlehu Esh Lo Nofach" (Iyov 20:26).
What is the meaning of "Nil'eisi Chalkel"?
Rashi: I could not bear the fire. Radak - I was forced to let it out, with my lips. Kalkel is bearing, like "u'Mi Mechalkel Es Yom Bo'o" (Mal'achi 3:2).
Malbim: I could not refrain from His Shelichus.