It is not your part to finish the task, yet you are not free to desist from it.
Rabbi Tarfon
Source: Pirke Avoth 2:16
Contributed by: Quiche
The day is short, the task is great, the laborers are lazy, the wage is abundant and the master is urgent.
Source: Talmud - Mishna Pirkei Avot 2:20
Contributed by: Barry
It is not incumbent upon you to finish the task. Yet, you are not free to desist from it.
Source: Talmud - Mishna Pirkei Avot (Ethics of the Fathers) 2:21