grasp; manage, govern; handshake (old usage)

(noun) a handshake; (usually referring to a valuable object) 'a grasp on' / 'the ownership of'/ '(to have) it in hand' / 'a hand on'

to make the mortgage; to have some security in hand (for the mortgage)

to have the mortgage or at least some security to 'hold in hand' as a guarantee for the mortgage