Why did Rivkah change the expression from "La'lin" to "La'lun"?
Rashi: In response to Eliezer's request for one night's lodging ("La'lin"), Rivkah responded with "Lalun" ? implying lodging for many nights. 1
Rashbam: "La'lin" is a noun; "La'lun" is a verb. 2
Seforno: ?Eliezer asked whether there was room for the camels to stay ??La'lin?, to which Rivkah replied that ? not only was there also also straw and fodder for the camels, but that ? there was also room for Eliezer and his men to lodge (?La'lun?).
Hadar Zekenim: Eliezer requested lodging for many nights. Rivkah responded "La'lun" - for one night, because, since her father's house was full of idolatry, it was not befitting to stay there longer than necessary.
Targum Onkelos and Targum Yonasan: There is no difference between them.
In keeping with the Midas ha'Chesed of Avraham, who always did more than was expected. Refer to 24:14:1:1. (Even though her father decides who may stay, she was sure that he would agree for money. If needed, she herself could pay with the gift that she just received! - PF).
See Rashbam who also explains why Eliezer added the word "Lanu" (for us) before "La'lin," whereas Rivkah did not insert "Lachem."