Is it true that Abu Bakr was with The Noble Prophet (saw) in the cave?

I beg your pardon my master, what is the meaning of His, The Exalted, saying: {he being the second of the two, when they were both in the cave, when he said to his companion: Grieve not, surely Allah is with us} [Surat Al-Tawbah 9:40]? And is it true that Abu Quhafa (Abu Bakr) was with The Noble Prophet (pbuh & his Family) in the cave?