What is vajra asana ? we can do it before and also after a meal.

Posture:  

Vajra-asana The Thunderbolt or Diamond Pose 

Translation:  

The Sanskrit word vajra means thunderbolt or diamond.     

Pronunciation:  

vuh-drah-sa-na  

    

Instructions:  

1.  The vajra-asana is a seated posture. Begin by sitting back on your heels and placing your knees, legs, and feet together.  

2.  Keeping the back straight place the palms of your hands down on top of your thighs.  

3.  Breathe gently through your nostrils and sit in this position for at least three minutes.

Comments: 

The vajra-asana is a versatile posture well suited for meditation, rest in between other seated postures, or as an aid to digestion. 
The vajra-asana is the position in various other yoga postures such as the Anjaneya-asana (salutation posture) and the ushtra-asana (the camel).  

Duration/Repetitions: 

The vajra-asana can be held for as long as is comfortable(and depending on the reason for doing the posture).