In plain words
That is why the mother too prays to God for her son's welfare.
Śaṅkara wins the Devī's grace
Every day Śaṅkarācārya's father would worship the Devī Rājarājeśvarī, offer Her milk as naivedya, and bring that prasāda to his wife and his son. One day, as he had to go to a neighbouring village on some work he could not avoid, he called his son Śaṅkara: “My son! Tomorrow you are to worship Rājarājeśvarī and offer Her the milk as naivedya. You and your mother may then take it,” he said. Next day Śaṅkara, bowing to his father's command, took milk in a cup, set it before the image of Rājarājeśvarī and prayed, “Mother! Accept this.” But however much time went by, the Mother did not come, and the milk in the cup was not used up. Śaṅkara was then a boy of six. “Mother! Every day You drink the milk my father brings, do You not? Then why do You not drink it today, when I have brought it? What sin have I committed?” he cried, deeply grieved. But he did not let go of his resolve. “Mother! If You do not drink this milk, I shall be one who has hurt the hearts of my mother and father. What is my life worth, if I cannot satisfy my parents? So I shall give up my life,” he vowed. Fearing that this innocent boy would take his life just as he had said, Rājarājeśvarī appeared before him: “My child! I am pleased with your Bhakti. Here, I am drinking the milk you have brought. Now be happy,” She said, and She drank up all the milk in the cup without leaving a single drop. Śaṅkara looked on. “Mother! If You drink up all the milk, what am I to give my mother as prasāda? She will think I drank it all myself. Every day my father would bring the milk You had drunk and give it to us. So give some of the milk back to me,” he said. Once the Gaṅgā has merged in the ocean, can anyone separate it out again? How could She bring back and give the milk She had once drunk? But Śaṅkara insisted that She must give him back at least a little of the milk. Otherwise, he argued firmly, he would get a bad name with his mother. Then Rājarājeśvarī took pity on him, and She Herself pressed out Her own milk and gave it to him. By drinking that milk alone Śaṅkara was able to make his victorious tour and receive the worship of the people. From that day all the Vedas, Śāstras and Upaniṣads were to him like a gooseberry in the palm of the hand.
Give God a place in your heart
A mother's Prema and God's grace: when these two come together, humanness is transformed into divinity. So revere your mother and father; pray to God. Bring your parents renown in the world; give God a place in your heart. This is what you must do. If you are good, great renown comes to your parents. Because Lava and Kuśa were great, great renown came to Sītā. In the battle with Rāma, Lava thought of his mother and cried, “If our mother Jānakī Devī is a true and chaste wife, may this man swoon under this weapon!”; and the moment he loosed the arrow, even Rāma swooned.