Tur, Yoreh De'ah 249:1
1 א
טור יורה דעה הלכות צדקה סימן רמט
שיעור נתינתה אם ידו משגת יתן כפי צורך העניים אם אין ידו משגת לכל צורך העניים יתן כפי השגת ידו כמה הוא יתן עד חומש נכסיו מצוה מן המובחר ואחד מי' מדה בינונית פחות מכן עין רעה
Regarding the amount to give- If your capacity is such that you can give an amount sufficient to meet the needs of the poor, you should give that much. If your capacity is not sufficient to meet all the needs of the poor, you should give as much as you are capable of. How much should you give? Up to 20% of your assets is the best way to fulfill the mitzvah. Ten percent is average. Less than that is stingy. [translation by AJWS]
3 ג

Suggested Discussion Questions:

1. How does this text stress the importance of tzedakah?

2. How does this text challenge the way one may view the money that they earn?

4 ד
Time Period: Medieval (Geonim through the 16th Century)