We are commanded to recite a benediction after eating, as it says "And you shall eat and be satisfied and bless Ha-Shem your G-d".¹ The sages further instituted benedictions before eating, drinking, or smelling fragrant odors; before performing commandments; and benedictions of praise to G-d on various occasions. Ezra and his court established the wording of all the benedictions; one should not depart from it. One who hears another reciting a benediction should respond "amen". One should avoid unnecessary benedictions, but it is praiseworthy to make many necessary ones, as David said "Every day I shall bless you".^2,a

One who receives good news should recite the benediction "...Who is good and does good"; on bad news one should recite "...the True Judge". On good events or on the performance of commandments that happen only infrequently one recites "...Who has kept us alive, and sustained us, and helped us reach this time". A sick person who recovers, a prisoner who is released, a seafarer who reaches land, and a traveller who reaches a settlement should publicly recite "...Who has bestowed all goodness on me".³ Other benedictions were instituted for one who sees unusual creatures or natural phenomena, or the new moon, as well as for many other occasions.^b

b) Benedictions over Food

The basic benediction before eating or drinking is "...by Whose word everything comes into existence"; but special benedictions were instituted over specific types of food: on things that grow in the ground, "...Who creates the fruit of the ground"; on the fruit of trees, "...Who creates the fruit of the tree"; on wine, "...Who creates the fruit of the vine"; on bread, "...Who brings bread forth from the earth"; and on certain other foods made from grain, "...Who creates kinds of food".^c Before eating bread or any food having liquid ingredients one must wash his hands by pouring fresh water (a volume equal to 1.5 eggs) over them from a vessel and then dry them.^d

After eating an amount the size of an olive or drinking a volume equal to 1.5 eggs the basic benediction is "...Who is the life of all the worlds". After foods made from grain, or wine, or grapes, figs, pomegranates, olives, or dates,⁴ one recites a benediction ending "...For the land and for the sustenance (or: the fruits)".^e After bread one recites four benedictions: "...Who feeds all", "...for the land and for the food", "...Who builds Jerusalem", and "...Who is good and does good..."; these were instituted by Moses, Joshua, David and Solomon, and the sages of the Mishnah, respectively.^f If three or more men eat bread together they should recite these benedictions together and precede them by reciting responsively "...Blessed be He (for ten or more men: our G-d) Whose food we have eaten and by Whose goodness we live."^g

Sources:
1. Deut. 8:10	a. 1:1-5, 13; 11:16
2. Psalms 145:2	b. 10:1-3, 8, 12ff.; 11:9
3. See Psalm 107	c. 8:1-2, 10; 3:2ff.
4. See Deut. 8:8	d. 6:1, 6-7, 20
	e. 8:1-2, 14; 3:2ff., 12-13
	f. 3:2; 2:1
	g. 5:2, 4