וְנָתַ֤נּוּ אֶת־בְּנֹתֵ֙ינוּ֙ לָכֶ֔ם וְאֶת־בְּנֹתֵיכֶ֖ם נִֽקַּֽח־לָ֑נוּ וְיָשַׁ֣בְנוּ אִתְּכֶ֔ם וְהָיִ֖ינוּ לְעַ֥ם אֶחָֽד׃
我們就把我們的女兒給你們，也娶你們的女兒歸我們；我們要與你們同住，成為一個民族。
Radak
הן עם אחד, they are all of one mind, as in Genesis 34,16 והיינו לעם “let us become a single nation.”
Rashi
We extended [a hand]. נָתַנּוּ is] the same as נָתַנְנוּ. The dagesh in the nun takes the place of the second nun, as in, “for all is from You, and from Your hand we have given נָתַנּוּ it to You,”4I Divrei Hayomim 29:14. and as in, “and we will give וְנָתַנּוּ our daughters to you.”5Bereishis 34:16.
Rashi
we were delivered Heb. נִתַּנוּ, like נִתַּנְנוּ. The “dagesh” in the “nun” is instead of another “nun,” like (II Chron. 14:10): “for we rely (תִשְּׁעַנוּ) on You,” like נִשְּׁעַנְנוּ. (Gen. 34:16): “... then we will give (וְנָתַנוּ) our daughters,” like וְנָתַנְנוּ.