We construct a family of pairwise commuting operators such that the Macdonald symmetric functions of infinitely many variables x 1 , x 2 , . . . and of two parameters q, t are their eigenfunctions. These operators are defined as limits at N → ∞ of renormalized Macdonald operators acting on symmetric polynomials in the variables x 1 , . . . , x N . They are differential operators in terms of the power sum variables p n = x n 1 + x n 2 + · · · and we compute their symbols by using the Macdonald reproducing kernel. We express these symbols in terms of the Hall-Littlewood symmetric functions of the variables x 1 , x 2 , . . . . Our result also yields elementary step operators for the Macdonald symmetric functions.