Which preposition to use with ungenerous

in Occurrences 9%

And in his walk a thousand things he said, Which I forgot, yet something with me staid; He did consult the nature of the Crime, And still concluded that 'twas just in him; He run o'er all his life, and found no act That was ungenerous in him, but this fact, From which the Justice took off the Disgrace, And might even for an act of Virtue pass; He did consult his Glory and his Pride;

to Occurrences 7%

He could be the most genial of comrades, the most considerate of masters, and he secured the devotion of his servants, as of his friends; but he was too overbearing to form many equal friendships, and apt to be ungenerous to his real rivals.

as Occurrences 1%

It should not be construed into an exultation misappliedan exultation as ungenerous as unwise, and made to minister, however indirectly, to that kind of censoriousness too apt to be produced in certain natures by success after trying reverses.

Which preposition to use with  ungenerous