When I desired their leave that I might pity him, they took from me the use of mine own house; charged me on pain of perpetual displeasure, neither to speak of him, entreat for him, nor any way sustain him.
There are no more uses of "sustain" identified with this meaning, but check unspecified meaning below.
—Ourself, by monthly course, With reservation of an hundred knights, By you to be sustain’d, shall our abode Make with you by due turns.
Alack, ’tis he: why, he was met even now As mad as the vex’d sea; singing aloud; Crown’d with rank fumiter and furrow weeds, With harlocks, hemlock, nettles, cuckoo-flowers, Darnel, and all the idle weeds that grow In our sustaining corn.
What he hath utter’d I have writ my sister: If she sustain him and his hundred knights, When I have show’d th’ unfitness,— [Re-enter Oswald.
] Friends of my soul, you twain Rule in this realm, and the gor’d state sustain.