One may have other duties to perform under the direction of the spiritual master, but he must first abide by the spiritual master’s order to chant a certain number of rounds. In our Krishna consciousness movement we have recommended that the neophyte chant at least sixteen rounds. This chanting of sixteen rounds is absolutely necessary if one wants to remember Krishna and not forget Him. Of all the regulative principles, the spiritual master’s order to chant at least sixteen rounds is most essential.
Chaitanya Caritamrita, Madhya Lila, 22.113