'Give' and 'grant' can have different uses. 'Give' can be used in a wide sense to refer to any act of providing someone with something. Something given may or may not have been asked for, whereas 'grant' often has a narrower sense of giving, or agreeing to give, something that another person has asked for, especially as an official or formal act. To the extent that the person who grants something has the power to agree or refuse do so, there is an imbalance of power between the person who grants and the person who requests. Condescension means "Having or showing an attitude of patronizing superiority", Someone who is your equal who says 'I will grant you fifty pounds' when you ask them informally for a loan could be said to be acting in a condescending manner, but they could simply be confused about the difference in meaning.
Give
Grant
Condescend