After the two prātipadika (Nominal Stems) idam and tad come respectively the affixes dā and rhil in the chandas (Vedas) and also other affixes.,
The affix दा comes after इदम् and र्हि after तद् ॥ Thus इदा 5.3.3, तर्हि 7.2.102. So also इदानीम् and तदानीम् ॥ As इ॒॒दा हि य॒॒मुप॑स्तुतिभि॒॒दा वा॒॒मस्य॑ भ॒॒क्तये॑ (Rig Veda VIII. 27. 11).,