What is reported about shortening prayer during travel and for how many days

`Sayyiduna Abdullah bin Abbas (may Allah be pleased with them) narrates that` the Noble Prophet (peace and blessings be upon him) stayed (at a place) for nineteen days and continued to shorten the prayers throughout.

Narrated Anas (may Allah be pleased with him): We traveled with the Prophet (peace and blessings of Allah be upon him) from Madinah to Makkah, and he continued to pray two rak‘ahs (for each prayer) until we returned to Madinah. (The narrator Abu Ishaq said:) I asked (Anas, may Allah be pleased with him): Did you stay in Makkah for some days? He said: Yes, we stayed there for ten days.