Can a father fulfill the Misva of Pidyon Ha’ben – "redeeming" his firstborn son by paying money to a Kohen – by appointing somebody else to pay the money on his behalf? Many Misvot – such as Berit Mila – can be fulfilled through a Shali’ah (agent). Is this true of Pidyon Ha’ben, or must the father personally give the money to a Kohen?
The Rama (Rav Moshe Isserles of Cracow, 1530-1572), in Yoreh De’a (305:10), cites a responsum of the Ribash (Rav Yishak Bar Sheshet, 1326-1408) in which it appears (at least from the question posed to the Ribash) that the father must personally perform the Misva of Pidyon Ha’ben, and cannot appoint somebody else to fulfill the Misva on his behalf. According to this view, this Misva can be performed only by the father, or by the child himself when he grows older. (See Aruch Ha’shulhan for a lengthy discussion of the possible rationale underlying this position.)
Most other Poskim, however, disagree, and allow fulfilling the Misva of Pidyon Ha’ben via an appointed agent. These include the Shach (Rav Shabtai Hakohen, 1621-1662), the Taz (Rav David Ha’levi Segal, 1586-1667), and the Gaon of Vilna (1720-1797). According to the consensus opinion, then, it is acceptable to appoint somebody to perform the Pidyon Ha’ben on one’s behalf.
Therefore, if the father is ill or infirm, Heaven forbid, and is incapable of personally performing his son’s Pidyon Ha’ben, he may appoint somebody else to perform the Misva on his behalf.
If the father is not ill or infirm, but is away from home, such as if he is traveling on business when the time for his son’s Pidyon Ha’ben arrives, he can – and should – perform the Misva in his current location, rather than appoint a Shali’ah. Since the infant does not have to be present at the Pidyon Ha’ben, the father can simply pay the required sum of money to a Kohen wherever he is, and this is preferable to appointing an agent to perform the Pidyon Ha’ben on his behalf. This is the ruling of the Hatam Sofer (Rav Moshe Sofer of Pressburg, 1762-1839), in his published responsa (Y.D. 264-5), as cited in Pit’heh Teshuba (Y.D. 305:20).
Summary: If a father is incapable of performing a Pidyon Ha’ben for his son, such as if he is ill or otherwise incapacitated, he may appoint somebody to perform the Misva on his behalf. If he is traveling at the time when the Pidyon Ha’ben is to take place, he should pay the money to the Kohen at his current location, as the baby does not have to be present at his Pidyon Ha’ben.