4 bonds of fellowship

1. Giving.

2. Kind words.

3. Beneficial help.

4. Consistency. 

This is from the Hatthaka Sutta. Hatthaka, along with Citta, were among the foremost lay Dharma leaders. The Buddha meets him at Aggalava Shrine which is among the status unknown places the Buddha went.

He also had 8 astounding qualities: "Hatthaka of Alavi is endowed with conviction. He is virtuous. He has a sense of conscience. He has a sense of concern (for the results of unskillful actions). He is learned. He is generous. He is discerning. He is modest."

Because he was such a good guy, he had 500 disciplines in Buddhism as a lay teacher, during the Buddha's lifetime. 

Citta was pure even though leading a lay life, a wealthy merchant from Suvatthi. He had 500 disciples too. 

The female equivalents were Khujjuttara and Velukandakiya.

"Khujjuttara was a servant to one of the queens of King Udena of Kosambi named Samavati. Since the queen was unable to go listen to the Buddha, she sent Khujjuttarā who went instead and became so adept that she was able to memorize the teachings and teach the queen and her 500 ladies in waiting." 

"Queen Samavati and the queen's 500 ladies in waiting all obtained the fruit (Pali: phalla) of the first stage of Enlightenment"