From Rashi's comment, that the Jewish people adopted the "profession of their ancestors" :and prayed (v.10), we can learn a practical lesson:
Jew should perceive prayer and, likewise Torah study as his "profession." He shouldn't feel the urge to pray only when a problem arises and he needs God's help. Similarly a person shouldn't study Torah only when he needs to know what to do. Rather he should perceive prayer and Torah study as his "profession" which he devotes himself to constantly, regardless of whether there is a direct need to do so or not.
Similarly, when drawing another Jew closer to Judaism, one should never think: "He does not look the type to become involved in lengthy prayer or in deep Torah study." For, every Jew is, at heart, capable of treating prayer and Torah study seriously, since it is his "profession." One simply has to reveal this potential by drawing the ·person with warmth and love.