1)
Why did she say "Tzror ha'Kesef Lakach b'Yado"?
1.
Rashi: He killed the best of them.
2.
Malbim (19-20): Do not fear lest my husband return home to get money needed for business.
2)
What is "l'Yom ha'Kese"?
1.
Rashi: It is the fixed time 1 . The same applies to "ba'Kese l'Yom Chagenu" (Tehilim 81:4).
1
Malbim: Therefore, do not fear lest he finish his business quickly and return. He will not return before the fixed time!