Comparative evidence

dʰei̯h₁, dʰei̯h₂, dʰei̯h₃

• OInd. dīdhī 'perceive', 'think', 'be intent' (upon); 'wish', 'desire' (MW: 481, Whitney 1885: 83)

• OInd. dhī 'perceive', 'think', 'reflect' (MW: 516, Whitney 1885: 83)

References

MW = Monier-Williams, M. 1899. A Sanskrit-English Dictionary. Clarendon Press.
Whitney 1885 = Whitney W. D. 1885. The roots, verb forms and primary Derivatives of the Sanskrit language. A supplement to his Sanskrit grammar. Leipzig