Is Washing the Mouth After Eating Required Before Praying?
Question

If I drink a liquid such as tea or juice and so on, and I want to pray, do I have to wash my mouth with water before praying? Does this also apply to the reading of the Quran from the Mushaf?
Praise be to Allah.It is not obligatory to wash the mouth after eating or drinking, whether one wants to pray or read the Quran . But it is recommended for him to do that, especially if what he ate or drank was at all greasy.  Ibn `Abbas (may Allah be pleased with him) narrated that the Prophet (blessings and peace of Allah be upon him) drank some milk, then he called for water and rinsed out his mouth and said: “It is somewhat greasy.” (Narrated by Muslim, 358)
An-Nawawi (may Allah have mercy on him) said: 
“This indicates that it is recommended to rinse out the mouth after drinking milk . The scholars said: This also applies to other kinds of food and drink; it is recommended to rinse the mouth lest any traces of it be left that might be swallowed whilst praying.” (Sharh Muslim by An-Nawawi)
It says in Al-Mawsu`ah Al-Fiqhiyyah (38/108): 
“Rinsing the mouth is recommended after one finishes eating, because of the report narrated by Suwayd ibn An-Nu`man (may Allah be pleased with him) according to which he went out with the Prophet (blessings and peace of Allah be upon him) in the year of Khaybar. When they reached As-Sahba’ – which is the furthest part of Khaybar – he prayed `Asr then he called for food, but nothing was brought to him except Sawiq (powdered roasted wheat or barley). He (blessings and peace of Allah be upon him) ordered that it be wetted with water because it was dry, and he ate and we ate, then he got up to pray Maghrib; he (blessings and peace of Allah be upon him) rinsed his mouth and we rinsed our mouths, then he prayed and he did not do Wudu. 
This Hadith indicates that it is recommended to rinse your mouth after eating. The benefit of rinsing the mouth before starting to pray after eating Sawiq, even though it is not greasy, is it may leave bits between the teeth or at the corners of the mouth, and trying to get rid of them may distract a person when he is praying.”
And Allah knows best.