Which episode is the little swallow learning?

In the sixth episode, the storm between the swallow and the queen finally subsided after the appearance of Qianlong, but the queen's hostility to the swallow was even stronger. Swallow wrote a letter of trust to Wei Zi in the dead of night. The swallow, who didn't know a few words before, brought a picture or didn't. Just when everyone could not guess the meaning of Swallow's painting, Wei Zi expressed the Swallow's painting in poetry, which made everyone admire Wei Zi's talent, especially Erkang. Wei Zi learned from the painting that the swallow was seriously injured before entering the palace, and Qianlong did not forget his mother. After careful consideration, Wei Zi decided to give up betraying his loved ones and keep this secret in his heart forever. Just as Wei Zi was leaving, Erkang could not help confessing to Wei Zi in order to keep Wei Zi. Erkang's action shocked Wei Zi, and he agreed to stay and no longer hide the feelings that had already arisen between them. In order to train swallows, Qianlong ordered swallows to attend classes with other senior brothers. Thanks to the help of Yongqi and Ertai, the swallow was able to survive this difficult time safely and brought laughter and vitality to the quiet class. Unexpectedly, at this time, the queen lowered her posture and showed her kindness to Qianlong, and finally got the right to raise swallows from Qianlong's mouth.