וַיֹּאמֶר֩ אֵלָ֨יו הָֽאֱלֹהִ֜ים בַּחֲלֹ֗ם גַּ֣ם אָנֹכִ֤י יָדַ֙עְתִּי֙ כִּ֤י בְתָם־לְבָבְךָ֙ עָשִׂ֣יתָ זֹּ֔את וָאֶחְשֹׂ֧ךְ גַּם־אָנֹכִ֛י אֽוֹתְךָ֖ מֵחֲטוֹ־לִ֑י עַל־כֵּ֥ן לֹא־נְתַתִּ֖יךָ לִנְגֹּ֥עַ אֵלֶֽיהָ׃
האָט גאָט צו אים געזאָגט אין חלום: יאָ, איך װײס אַז אין דער ערלעכקײט פֿון דײַן האַרצן האָסטו דאָס געטאָן, און איך האָב דיך אױך געװאָלט פֿאַרמײַדן פֿון זינדיקן צו מיר, דרום האָב איך דיך ניט געלאָזט זיך צורירן צו איר.
Rashi
'ידעתי כי בתם לבבך וגו I KNOW THAT IN THE INTEGRITY OF THY HEART etc. — It is true that at first you had no intention of sinning, but you cannot claim innocency of hands (Genesis Rabbah 52:6) —
Chizkuni
גם אנכי ידעתי כי בתם לבבך וגו׳, “also I am aware that you have acted innocently, etc;” G-d , by saying: גם, includes that not only does He know that Avimelech had not raped Sarah in his heart but that his hands had remained clean also.
Or HaChaim
ויאמר אליו האלוקים. G'd said to him (Avimelech). He agreed that Avimelech had not yet become guilty of death considering he had been convinced that Sarah was not married. As to his integrity, however, this was another matter. Whereas he might not have literally "robbed" Sarah [i.e. she did not belong to Abraham. Ed.], nonetheless he had employed the authority of being the king which is a kind of violence. At the very least "his hands were not clean in the matter."
Siftei Chakhamim
צוטריטלעך נאָר פֿאַר פּרעמיום־מיטגלידערRav Hirsch
צוטריטלעך נאָר פֿאַר פּרעמיום־מיטגלידערRashi
because לא נתתיך I PERMITTED THEE NOT — It was not of your own will that you did not touch her, but it was “I” who withheld you from sinning, and “I” did not permit you the possibility to touch her (Genesis Rabbah 52:7). Similar examples of נתן in sense of permitting are, (31:7) “God permitted him not (לא נתנו)” and (Judges 15:1) “But her father did not permit him (ולא נתנו) to go in”.