Fasting on 9 or 10 and 11 Muharram!

When the Messenger of Allah (PBUH) himself fasted on the day of Ashura and ordered the Companions to fast; So the Companions, may Allah bless them and grant them peace, said to him, O Messenger of Allah! Do Jews and Christians ever honor this day? (Perhaps it will be intended to submit that by fasting, we also honoured this day, as if we started to imitate them in an act, then the Prophet (peace and blessings of Allah be upon him) said: “If Allah If he wants, next year we will fast on the ninth date as well. Hazrat Ibn Abbas, may God be pleased with him, says that he passed away before the coming of the next year. (Sahih Muslim: 1134)