Kitzur Shulchan Aruch, Rabbi Shlomo Ganzfried
Chapter 69 : Laws of the Minchah Prayer
It is forbidden to begin eating even a small meal shortly before [the time of] Minchah ketanah. By shortly we mean one-half hour before. If you do not sit down to a meal, but eat or drink only casually, [such as] fruit or any cooked dish, even if it is [made] of the five grains, some authorities permit it. But, it is best to be stringent even in this regard. Similarly, it is forbidden to enter a bathhouse or to [have] a haircut shortly before Minchah ketanah. An elaborate meal, such as at a wedding or a circumcision and the like, must not be started even shortly before [the time] of Minchah gedolah; therefore it is prohibited to begin such a meal beginning from midday. It is best to wait until the time [for] Minchah gedolah and pray [Minchah] before the meal. In communities where the people are summoned to the synagogues and it is your usual practice to attend synagogue to pray communally, [then,] you may start a small meal close [to the time] of Minchah ketanah, and even afterward, provided that immediately upon being called to synagogue you interrupt whatever you are doing [in order] to pray. When it is close to Minchah Ketanah, an elaborate meal may not be started even where [people] are called to synagogue; and even close [to the time] of Minchah gedolah it is preferable to be stringent.
The Minchah prayer also requires washing of the hands until the joint (i.e. the wrist) as does the Shacharis prayer as was explained above in Chapter 12, paragraph 5 and paragraph 6 (See Chayei Adam Chapter 33, para. 6, and the Shulchan Aruch of the Tanya, Chapter 92, footnote 23). Likewise, you must wash your hands, for the Maariv prayer, if you were interrupted after Minchah, and for Musaf if you were interrupted after Shacharis.