As his life drew to a close, Yaakov Avinu became ill. When his son Yosef was informed of this, he traveled to his father's bedside together with his two sons. The Torah notes Yaakov's response to the appearance of his son and grandchildren: "[he] exerted himself and sat up on the bed" (Bereishit 48:2.)
The Da'at Zekainim explains that Yaakov wanted to sit up in bed while he blessed his children, rather than doing so while lying down. In doing so, Yaakov wanted to make it perfectly clear that his blessing was not a desperate gesture from a dying man who was not in full control of his mental capacities, that he was fully alert.
This explanation seems difficult. Why would it be of concern whether or not the recipients of a blessing think Yaakov is too sick? After all, isn't a blessing merely a form of prayer to HaShem asking that the recipient be endowed with a particular gift? If Yaakov's words were directed to HaShem, why does it matter what the recipients think?
Rav Simcha Zissel Broyde (the late Rosh Yeshiva of the Chevron Yeshiva) notes that we see from here that there is a substantial difference between a prayer and a blessing. A prayer is a personal communication between an individual and HaShem. A blessing, however, is an expression of good will and hope given by one person to another. The impact of a blessing therefore is only as powerful as the belief and confidence of the recipient in the well-wisher's words. Only to the extent that the recipient is willing to accept the blessing can it result in actual benefit. Yaakov sat up to ensure that there would be no doubt in their minds that he was fully aware of the eternal meaning of his words.
(Based on the Sefer, "L'Chaim")
Rabbi Michael Macks will be contributing weekly divrei torah as he is able