Immeasurable Merit

1. A person who feeds just one brahmacari(Celibate) earns ten times more merit than one who feeds ten good brahmanas(Learned Persons) in his own house.  
2. But a thousand times more merit than is earned by feeding a brahmacari is achieved by donating land to the needy and respectable brahmana, and a 
3. thousand time more than that is earned by giving away a virgin girl in marriage to a young, well-educated, responsible man.  
4. Ten times more beneficial than this is educating children properly on the spiritual path, without expecting any reward in return.  
5. Ten times better than this, however, is giving food grains to the hungry.  Indeed, giving charity to those in need is the best of all, and there never has been or ever will be a better charity than this.   O son of Kunti, all the forefathers and demigods in heaven become very satisfied when one gives food grains in charity. 
6. But the merit one obtains by observing a complete fast on Ekadasi cannot be measured.  

Source

Margasirsa-krsna Ekadasi, or Utpanna Ekadasi, from the Bhavisya-uttara Purana