בראשית כג,ב: וַתָּמָּת שָּרָּה בְּקִרְּ יַת אַרְּ בַע הִוא חֶבְּרוֹן בְּאֶרֶץ כְּנָּעַן וַיָּבֹא אַבְּרָּהָּם לִסְּפֹד לְּשָּרָּה וְּלִבְּ כֹ תָּהּ:
The Baal HaTurim writes that the letter Kaf is small to indicate that Avrohom's crying for the death of Sarah was limited. The Gemara (Moed Katan 27b) explains that the first three days after a death are for crying and the last four days of the "shivoh" are for eulogy. Avrohom was at Har HaMoriah when he became aware of Sarah's death and immediately set out for Chevron. This was a three-day trip, as we find that from Chevron to Har HaMoriah for Akeidas Yitzchak took three days (22:4). When he reached home the main time for crying had passed, so his crying was limited. It seems that this would also explain why he first eulogized her, and only afterwards cried for her passing, "lispode l'Soroh v'livkosoh."
The letter Kaf (20) underscores the difference between the age of Sarah when she dies (127) and the age of Yaacov at his death (147). They were linked in many ways including being the first and last ones buried in the Cave of the Machpaleh.
