In plain words
If God is to help us in trouble and sorrow, we must have done in the past some small kindness or some sacred act
In the same way, if God is to come to any man's aid in his troubles, sorrows and griefs, we must have done some fitting small kindness or some small sacred act. The people of Bhārata have handed down a sādhana: "Man must serve God by good karmas and good conduct." If we do no good karmas now, God cannot come to our aid at the right time. The karma you do today is what stands as the ground of the future. So if we are to receive good fruit in the future, we must sow good seeds in the present. The good karma or the bad karma you have done comes to you in the future as bad fruit or good fruit. It was on this ground that the Upaniṣads warned us, "Tasmai namaḥ karmaṇe," to bow to karma.
At all times we must use good words. We must not use words that hurt anyone. If someone is wounded, the doctor puts a bandage on it, applies medicine and heals it. But no one can heal a heart wounded by words. So we must never use words that hurt the hearts of others. Even if the words of others hurt you, you must try to bear it; but if you also speak so as to hurt them in return for that hurt, how can you be a good man? You become the same as he is. That is why Bhīṣma said, "Dharmaja! A plant or a tree cut down with a sharp sword will sprout again. But a mind broken by words will never sprout again." With a mind broken by words you can achieve nothing more.