"Don't make mountains out of molehills" means don't turn a trivial matter into a large concern. Yeshua seems to espouse a similar sentiment when He chastises the religious for scrupulously observing the small details of God's Law while ignoring the "weightier provisions of the Torah" (Matthew 23:23). Nevertheless, Yeshua taught His disciples to keep even the smallest of the Torah's commandments. He said, "Whoever then annuls one of the least of these commandments, and teaches others to do the same, shall be called least in the kingdom of heaven" (Matthew 5:19).
Have you ever wondered what the "least of these commandments" is? According to the Talmud, one of the least of the commandments is Deuteronomy 22:6-7's admonition to drive away a wild bird from her nest before taking her young:
If you happen to come upon a bird's nest along the way, in any tree or on the ground, with young ones or eggs, and the mother sitting on the young or on the eggs, you shall not take the mother with the young; you shall certainly let the mother go, but the young you may take for yourself, in order that it may be well with you and that you may prolong your days. (Deuteronomy 22:6-7)
The Talmud points out that, although the commandment of driving away the mother bird is the least of the commandments, it carries the same reward as the weighty commandment of honoring one's father and mother:
Honor your father and your mother, as the LORD your God has commanded you, that your days may be prolonged and that it may go well with you on the land which the LORD your God gives you. (Deuteronomy 5:16)
In his famous work The Guide to the Perplexed, Maimonides (Rambam) explains that the commandment to drive the wild mother bird away before taking the young from the nest is an act of mercy. It would pain the mother bird to see her offspring taken. By driving her away before taking her young, we reduce her suffering. If God so cares for the emotional pain of a simple bird, how much more so should we show compassion to all of his creatures, especially our fellow man.
If Maimonides is correct, the law of driving away the wild bird is a commandment to show mercy and kindness to all God's creatures, to exercise compassion and empathy and to do our best to alleviate the suffering and emotional pain of others.
In that case, it's not a small commandment at all. Instead, it belongs to a category of laws that Yeshua called the "weightier provisions of the Torah" (Matthew 23:23).