A mudra is a seal to hold or direct prana (energy). The heart mudra (Hridaya Mudra) is made with the fingers by bending the first finger into the root of the thumb and then bringing the tips of the 2nd and 3rd fingers to touch the tip of the thumb. See the picture above.
This hand gesture is said to divert energy flow from the hands to the heart area, helping to address and release pent-up emotion. Sit with the spine up straight and the backs of your hands on your thighs. Take the mudra and focus your breath in the heart space. Meditate for as long as is comfortable.